hi all, I have a 2000 disco td5 with 116k miles on the clock. I have never had a land rover before so all new to me, first thing is I have a high pitched whistle when reving, and sometimes when warm and under load it sounds like an air leak. I have looked at all the turbo hoses but they all look ok so is this just normal?
Also sometimes under load there is a slight misfire. I have replaced injector harness and cleaned ecu plug, changed oil and filters and fitted new genuine MAF.

These could all be normal sounds for a td5 but like I say its all new to me. also do all td5's sound like a tractor.

High pitched whistle is the turbo spinning, it shouldn't be too loud on a TD5. If it sounds like an air leak to could be a split hose, or it could be a cracked exhaust manifold. Do you get any smoke when this happens? Could be hoses to the inter-cooler - there is quite a long run of them.

In terms of sounds, depends what you mean by a tractor. They are a diesel so can sound a bit alarming at times but shouldn't be excessively noisy - at tick over they are relatively quiet, if sometimes a little tappety sounding. Noise can change depending on load, throttle opening, temperature etc.